just curious what role does nitrate play with algae? in a tank with 0 nitrate can algae form? lets assume this is a non planted tank.

Byron

10-15-2009 06:05 PM

Nitrate is a chemical compound of one part nitrogen and three parts oxygen, hence the symbol NO3. It is a naturally occurring ion, a product of the oxidation of nitrogen by micro-organisms in plants, soil and water. In the aquarium, bacteria produce nitrate from nitrite, which itself comes from ammonia and ammonium. Nitrate is thus a form of nitrogen.

Algae is a plant, and all plants need nitrogen as one nutrient. As I explained in two prior threads, plants have the ability to use all three forms of nitrogen normally available in an aquarium: ammonia/ammonium, nitrite and nitrate; but most prefer to use the free ammonia or ammonium. Algae and plants need more than just nitrogen, they also need CO2, macro-nutrients and micro-nutrients, and all this in the presence of light.

Algae generally occurs from an excess of organic materials and poor water quality, or an excess of nutrients. In the absence of higher plants, these nutrients are readily available since they enter the aquarium through fish food and water. An excess of soluble iron can also cause a bloom of single-celled or filamentous "green" algae. Another reason to avoid dosing individual iron unless it is in balance with all 17 nutrients that plants require.

It is therefore possible to have nitrates without having algae, if the other nutrients required for algae/plants are not present. Similarly, algae can be present without nitrate since the algae does not need nitrate in order to obtain its nitrogen. Without nutrients, there can be no algae.

In aquaria with problem algae, the nitrates are usually high. Nutrients that feed the algae also contribute to the nitrogen cycle, along with the fish and other bacteria. Excessive levels are bound to impact several processes ongoing in the aquarium.

Byron.

MoneyMitch

10-15-2009 06:15 PM

thank you for your insight byron greatly appreciated. i know feel that i fully understand algae and nitrate relationships.

baron von bubba

10-15-2009 08:23 PM

Quote:

Originally Posted by Byron
(Post 257949)

It is therefore possible to have nitrates without having algae, if the other nutrients required for algae/plants are not present. Similarly, algae can be present without nitrate since the algae does not need nitrate in order to obtain its nitrogen. Without nutrients, there can be no algae.

please clarify this the above in bold?
surely the last thing you would want is any nutrient at all to be lacking, is this not one of the things that actually causes algae?
isnt it a much better idea to make sure the plants have everything they need in non limiting supply?
as soon as the plants struggle or stall will they not release more organic waste themselves that will cause algae to trigger?
algae is an opportunist and as you say likes a fluctuating environment. keep the nutrient levels non limiting so the plants grow healthy and youre half way there!

Quote:

Originally Posted by Byron
(Post 257949)

In aquaria with problem algae, the nitrates are usually high. Nutrients that feed the algae also contribute to the nitrogen cycle, along with the fish and other bacteria. Excessive levels are bound to impact several processes ongoing in the aquarium.

Byron.

maybe.
but it'd probably be a far more realistic to say in aquaria with problem algae the lighting is too high for the levels of available CO2, nutrients and/or flow

as you say high nitrate are an end product of the nitrogen cycle, would that not mean there has been levels of ammonia first? does it not make more sense that this sign of a possibly un healthy/un stable environment is far more likely to be a cause of algae than the end product of nitrate?

Byron

10-15-2009 08:42 PM

The original post in this thread asked about a non-planted tank.

As for the bold statement, nitrate is only a form of nitrogen. Algae can't live with only nitrate, it needs all the other nutrients.

The light itself does not cause algae. Nutrients have to be present in light. Plants are higher forms that can photosynthesize faster than algae, which is why turning the lights out mid-day for an hour or two will not negatively affect the plants but can impact algae which needs longer light duration to compete. And if CO2 is the limiting factor, then light that is beyond the balanced intensity for the CO2 will create an environment for algae because they are better able to obtain carbon from carbonates. Some plants are quite good at this, Vallisneria for example, which is why is grows so well in alkaline water which has a higher carbonate hardness; but others are not and rely far more on CO2 and these are then at a disadvantage in such a situation. Which is why algae frequently appears faster in alkaline water than in acidic, all else being equal.

I previously noted that algae occurs due to high organic materials and poor water quality, as well as from excess nutrients.

BH

baron von bubba

10-15-2009 08:55 PM

Quote:

Originally Posted by Byron
(Post 258080)

The original post in this thread asked about a non-planted tank.

As for the bold statement, nitrate is only a form of nitrogen. Algae can't live with only nitrate, it needs all the other nutrients.

The light itself does not cause algae. Nutrients have to be present in light. Plants are higher forms that can photosynthesize faster than algae, which is why turning the lights out mid-day for an hour or two will not negatively affect the plants but can impact algae which needs longer light duration to compete. And if CO2 is the limiting factor, then light that is beyond the balanced intensity for the CO2 will create an environment for algae because they are better able to obtain carbon from carbonates. Some plants are quite good at this, Vallisneria for example, which is why is grows so well in alkaline water which has a higher carbonate hardness; but others are not and rely far more on CO2 and these are then at a disadvantage in such a situation. Which is why algae frequently appears faster in alkaline water than in acidic, all else being equal.

I previously noted that algae occurs due to high organic materials and poor water quality, as well as from excess nutrients.

BH

ah yeah, i missed the non planted bit! :0)

thanks for clarification it seemed you were saying as long as one nutrient was not there then algae wouldn't grow.

but this is interesting none the less.

algae like unstable conditions right?
so how is it that turning the lights off for one or two hours help stop it?

isnt the function a of light siesta to give time for co2 levels to "recharge" therefore keeping the plants healthier?

so would it work to have lighting in two hour sessions with and hour break between each, would this not discourage algae even more than one lighting break?

Jack Middleton

10-16-2009 03:13 AM

George farmer did a write up on siesta's and it turns out they actually encourage algae!

1077

10-16-2009 03:35 AM

Seems to me algae is a plant or plantlife. Makes since to me that limiting light, or blacking out a tank, would stifle growth. But I ain't no plant person at least in regards to the aquarium.
I can grow orchids and gardenias in the boileroom here at work but my success with plants in the aquaria have been spotty at best.
Let's not forget were talking about non planted tanks now and how or what contributes to alage growth in that regard.

1077

10-16-2009 07:13 AM

I am always willing and eager to learn. Perhaps those who have dismissed the often accepted reasons for algae growth would share their opinions on the primary cause of algae. Not that which contributes to it ,but rather the root cause. I'm all ears, Just ask my mother.

Jack Middleton

10-16-2009 07:39 AM

Quote:

Originally Posted by 1077
(Post 258310)

I am always willing and eager to learn. Perhaps those who have dismissed the often accepted reasons for algae growth would share their opinions on the primary cause of algae. Not that which contributes to it ,but rather the root cause. I'm all ears, Just ask my mother.

Undetectable ammonia
Low, or unstable CO2
Too much light for the ferts and CO2 available
Lack of NPK+traces
Lack of flow

Baron von bubba- please feel free to add any more as i believe i have forgotten a few